State of darkness protection in strategic lighting documents of 10 European cities

Minimizing the adverse effects of lighting and enabling safe and justified darkness are prerequisites for sustainable urban lighting. In this paper, we analyse the justifications and measures that 10 European cities have documented for protecting darkness in their strategic lighting documents such as lighting masterplans. Our aim is to form an overview of the state of darkness protection in European urban settings at the beginning of the 2020s. We hope that the situational overview helps the existing good practices to disseminate and supports steering of measures and development work related to urban lighting and darkness protection at different levels of governance and in research. After exploration of a larger set of material, ten cities and 1-2 documents from each were selected for thematic analysis: three Finnish cities, four other cities of similar size in the northern half of Europe and three more southern European cities. The most common justifications given by the cities for protecting darkness were ecological, relating to biodiversity, ecosystems and species of nature. Human-centred justifications included perspectives of health, well-being and comfort, cultural significance of darkness, and the notion that protecting darkness also creates more legible urban space. The cities present a wide variety of measures for protecting and restoring darkness and mitigating the harmful effects of lighting. Thematic outline and several categories are presented with examples in the article. To conclude, many good practices already exist, and cities would benefit from learning from each other. It seems important to raise awareness about the values of darkness, as well as of solutions that integrate the needs for lighting with the needs for darkness. The analysis raises further research questions on the use and usability of strategic lighting documents and long-term strategic planning to restore and protect urban darkness.